A137639 Triangle read by rows, A026794 * A051731.

1, 2, 1, 3, 0, 1, 5, 2, 0, 1, 7, 1, 0, 0, 1, 11, 3, 2, 0, 0, 1, 15, 2, 1, 0, 0, 0, 1, 22, 6, 1, 2, 0, 0, 0, 1, 30, 5, 3, 1, 0, 0, 0, 0, 1, 42, 9, 2, 1, 2, 0, 0, 0, 0, 1, 56, 9, 3, 1, 1, 0, 0, 0, 0, 0, 1, 77, 16, 6, 3, 1, 2, 0, 0, 0, 0, 0, 1

Offset

1,2

Comments

Left border = A000041 starting with offset 1: (1, 2, 3, 5, 7, 11, 15, ...).

Row sums = A137640: (1, 3, 4, 8, 9, 17, 19, ...).

Links

Table of n, a(n) for n=1..78.

Formula

A026794 * A051731 as infinite lower triangular matrices.

Example

First few rows of the triangle:
   1;
   2, 1;
   3, 0, 1;
   5, 2, 0, 1;
   7, 1, 0, 0, 1;
  11, 3, 2, 0, 0, 1;
  15, 2, 1, 0, 0, 0, 1;
  22, 6, 1, 2, 0, 0, 0, 1;
  30, 5, 3, 1, 0, 0, 0, 0, 1;
  ...

Crossrefs

Cf. A000041, A137640, A026794, A051731.

Sequence in context: A158902 A137587 A168021 * A239631 A113288 A199580

Adjacent sequences: A137636 A137637 A137638 * A137640 A137641 A137642

Keyword

nonn,tabl

Author

Gary W. Adamson, Jan 31 2008

Status

approved